If you have to file Form 3520 this year (Annual Return to Report Transactions With Foreign Trusts and Receipt of Certain Foreign Gifts), you can do that manually, by downloading the tax form itself and the instructions at the following internet links:
https://www.irs.gov/pub/irs-pdf/f3520.pdf
https://www.irs.gov/pub/irs-pdf/i3520.pdf
You can then use TurboTax to complete your tax return normally if you wish. While Form 3520 must be printed and paper filed, by mail (it cannot be e-filed), there is no reason that this should interfere with your regular income tax return preparation and e-filing. Form 3520 is a disclosure document, really, and there is never any actual tax due with it.
However, if you meet the conditions of having to file Form 3250 (receipt of more than $100,000 in value from a foreign source), then failure to file it can lead to a fine of up to 5% per month (maximum of 25%) of the amount received.
Form 3520 does not come as part of the TurboTax software package. However, the form is easy enough to fill out by hand. Also, hiring a professional local tax preparer to do it for you is an option as well. The two things are really separate activities that need not interfere with each other.
[From: https://ttlc.intuit.com/questions/3686254-i-need-to-file-form-3520-this-year-can-i-still-use-turbota...]
